In mathematics, the imaginary part of a complex number z is the second element of the ordered pair of real numbers representing z, i.e. if z = x + iy then the imaginary part of z is y.

In terms of the complex conjugate , the imaginary part of z is equal to

The imaginary part of z is denoted Imz or . It is not holomorphic.

If a complex number is written as re^iθ, then the imaginary part is rsinθ. (See Euler's formula.)

See also

• Real part
• Imaginary number
• Complex number